The invention relates to improvements in machines for making hot beverages, such as coffee, tea or hot chocolate. More particularly, the invention relates to improvements in electrically operated machines for making hot beverages and to improvements in means for heating a liquid (such as water or milk) in such machines before the liquid is caused or permitted to contact an aromatic agent, e.g., comminuted coffee beans, tea leaves or chocolate powder. The invention will be described primarily in connection with coffee making machines; however, it is to be understood that the invention can be embodied with equal or similar advantage in tea making machines, in machines for making hot chocolate and/or in any other electrically operated machines which are designed to heat a liquid prior to causing or permitting the heated liquid to contact a flavoring agent.
A coffee making machine normally comprises a tank or another suitable source of water, a filter holder which can receive a supply of comminuted coffee (normally in a filter bag), a device for electrically heating water between the tank and the filter holder, and a warming plate or another suitable support for a pot or another vessel which is to receive hot beverage from the filter holder. Reference may be had, by way of example, to "Euro/Brew/Aroma" Coffee Maker No. 154 and to "Euro/Brew/Signal" Coffee Maker No. 152, both manufactured and distributed by the assignee of the present application.
The heating device in a conventional electric coffee maker normally comprises a bent (particularly U-shaped) water-conveying conduit which is in direct contact with one or more electric heating elements. Such heating element or elements can be provided on a bent (e.g., U-shaped) pipe which directly surrounds the conduit and is in large-area surface-to-surface contact therewith so as to ensure a satisfactory exchange of heat and predictable heating of water in the conduit to a desired temperature while the water flows from the tank toward and into a riser which conveys heated water into the filter holder wherein heated water is permitted to contact a supply of comminuted coffee beans. The inlet of the water-conveying conduit receives cold water from the tank and the outlet of the conduit delivers hot water into the lower end portion of the riser.
In presently known coffee making machines, the entire water-conveying conduit (inclusive of the inlet and outlet) is located in a substantially horizontal plane when the machine is set up for use, and the conduit is normally installed in the hollow base portion or leg of the housing of the coffee making machine. On the other hand, the tank is normally mounted in or on the housing in upright position, and the same applies for the riser which delivers hot water into the filter holder. Therefore, conventional coffee making machines must employ complicated elbow-shaped or similarly configurated discrete coupling devices which serve to connect the horizontal inlet of the conduit with an outlet of the water tank and to connect the horizontal outlet of the conduit with the lower end portion of the riser. As a rule, each coupling device has a first elastic end portion which is connectable with the outlet of the tank or with the lower end portion of the riser, and a second elastic end portion which is connectable with the inlet or outlet of the water-conveying conduit. Such coupling devices contribute significantly to the initial cost of the machine, not only because they are rather expensive but also because they cannot be readily assembled with water tanks, risers and water-conveying conduits in automatic machinery, e.g., in a production line.